The research proposed will investigate the relationship between Antisocial Personality Disorder (ASPD) and alcohol induced aggressive responding. The neurochemical mechanisms of alcohol's effects upon these behaviors under controlled laboratory conditions will be determined with a specific focus on the neurotransmitter serotonin. Specific Aim 1. To determine the effect of tryptophan depletion and augmentation on aggressive responding in alcohol drinking subjects with Antisocial Personality Disorder (ASPD) and alcohol drinking non-ASPD controls. Hypothesis Related to Specific Aim 1: Alcohol drinking subjects with ASPD will show a greater increase in aggressive responding on the Point Subtraction Aggression Paradigm (PSAP) after tryptophan depletion than non-ASPD alcohol drinking subjects. Specific Aim 2. To determine the effect of tryptophan depletion and augmentation on alcohol induced aggressive responding in subjects with ASPD and alcohol drinking controls. Hypotheses Related to Specific Aim 2: a. Within subjects, aggressive responding on the PSAP after the alcohol dose will be greater after tryptophan depletion than after tryptophan augmentation. b. Subjects with ASPD will show a greater increase in aggressive responding than non-ASPD subjects in the alcohol dose and tryptophan depletion condition. Specific Aim 3. To measure serotonin function in ASPD subjects and controls using a neuroendocrine challenge with the 5-HT1B/1D agonist zolmitriptan. Hypothesis Related to Specific Aim 3: Alcohol drinking subjects with ASPD will have a significantly blunted growth hormone response to zolmitriptan neuroendocrine challenge compared matched alcohol drinking controls. Specific Aim 4. To determine if the 5-HT1B/1D agonist zolmitriptan blocks alcohol induced aggressive responding in subjects with ASPD and matched controls. Hypotheses Related to Specific Aim 4: a. The 5-HT1B/1D agonist zolmitriptan will decrease alcohol induced aggression in all subjects. b. Subjects with ASPD will show the greatest decrease in alcohol induced aggression after zolmitriptan administration. c. The decrease in alcohol induced aggression will inversely correlate with the peak growth hormone response to zolmitriptan in subjects who have completed Aim III.